1. The Israelites had forsaken God and Christ, who were the
    source of living water. (Jer 2:13)
    Jn 4:13-14, Jn 7:37-39, Rev 21:6, Jn 1:10-11, Acts 3:14-15

In the Old Testament, the Israelites forsook God, the source of living water. (Jeremiah 2:13)

Jeremiah 2:13 For my people have committed two evils; they have forsaken me the fountain of living waters, and hewed them out cisterns, broken cisterns, that can hold no water.

Jesus gives us the Holy Spirit, the water of eternal life. (John 4:13-14, John 7:37-39, Revelation 21:6)

John 4:13 Jesus answered and said unto her, Whosoever drinketh of this water shall thirst again:
14 But whosoever drinketh of the water that I shall give him shall never thirst; but the water that I shall give him shall be in him a well of water springing up into everlasting life.

John 7:37 In the last day, that great day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink.
38 He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water.
39 (But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.)

Revelation 21:6 And he said unto me, It is done. I am Alpha and Omega, the beginning and the end. I will give unto him that is athirst of the fountain of the water of life freely.

The Israelites did not accept Christ Jesus, the source of living water, but rather killed him. (John 1:10-11, Acts 3:14-15)

John 1:10 He was in the world, and the world was made by him, and the world knew him not.
11 He came unto his own, and his own received him not.

Acts 3:14 But ye denied the Holy One and the Just, and desired a murderer to be granted unto you;
15 And killed the Prince of life, whom God hath raised from the dead; whereof we are witnesses.